This invention relates to network operations, and in particular to the allocation of addresses in networks such as the internet.
In order to be able to make a connection to an entity over a network, for example a computer network such as the internet, that entity must have an address allocated thereto. However, in some networks, the number of available addresses is smaller than the number which could be required.
To alleviate this problem, recognising the fact that many network users will only want to be connected to a network for a relatively small proportion of the time, internet addresses are typically allocated to a user temporarily. Such addresses can then be reallocated when a connection is terminated and, when the user wishes to reconnect, he will again receive an address, which is unlikely to be the same as before. In one variation of this widely used principle, WO96/39770 describes an address management system in which a user at a remote access device receives a username, and an internet protocol (IP) address. When the user disconnects, he loses the IP address, but, when he reconnects, he receives the same IP address as before.
However, this cannot solve difficulties caused by an excessively large number of users requiring permanent network connections, and hence permanently occupying network addresses. For the user, it may be advantageous to have a permanent connection, since this allows the user to be contacted by other entities, and also allows the user to resume activity, after a pause, without going through a lengthy dial-up process. In a network such as the internet, the number of available network addresses is insufficient to allow every user to occupy a network address permanently, particularly in view of the expected growth in the numbers of internet users.
In accordance with aspects of the invention, some of the problems caused by the limited availability of network addresses can be overcome. Specifically, aspects of the invention allow a user to obtain some of the benefits of a permanent network connection, without requiring the user to occupy an address permanently.
Specifically, in one aspect of the invention, a user may be in an idle connected state. In this state, the entity does not have an allocated network address but, in the event that another entity wishes to contact the first, an address is allocated thereto.
More particularly, in one aspect of the invention, when an entity wishes to reach a user in an idle connected state, the user can be forced to request a network address which can be used for the connection.
In a further aspect of the invention, there is preferably provided a server which contains a database of network addresses allocated to network users, the server having the ability, when it determines that a particular user has no address allocated thereto, to force that user to obtain an address.